Potassium is an alkali metal in group IA of the periodic table with atomic number 19, an atomic weight of 39.102, and a density of 0.86 Mg/m 3. Its melting point is 63.7 C, and it boils at 760 C. The ...

After the third energy level has 8 electrons, the next electron goes into the fourth level. 4th Period: Potassium and Calcium—Electrons go into the fourth energy level. A small piece of sodium metal ...

Key Features of the Modern Periodic Table: Arranged by Atomic Number: Elements are arranged in order of increasing atomic ...

The modern periodic table is based closely on the ideas he ... For example, lithium (Li), sodium (Na) and potassium (K) all have the same kind of reaction with water. The group of elements below ...

They include lithium, sodium and potassium, and are placed in the first vertical column on the left of the periodic table. All the Group 1 elements are very reactive, and all react with water to ...